Chiang Saen is a northern Thai city and district capital along the Mekong. It anchors trade, history and risk at the Kok river confluence.
Heavy metal contaminants from unchecked upstream mining have entered the Mekong, imperiling millions who rely on the river for farming and fishing. Thailand bears the brunt, with downstream concerns spreading to Cambodia and Vietnam as officials monitor rising heavy-metal levels and communities adapt to changing livelihoods. This update highlights current impacts and local responses as cross-border pollution persists.